If you travel on the London Underground any time soon you may have to do a double take when planning your journey. A series of carefully placed stickers have appeared on Underground maps around the City, each one altering the Circle Line in subtle but clever ways. Some of the stickers carry political messages, others are there just to make us smile. But all of them are there to make us think, so even though they won’t help you get to where you’re going, they might perhaps point you in a slightly new direction.